The Digital Visual Interface (DVI) and High Definition Multimedia Interface (HDMI) have become very popular digital interfaces in the consumer electronics arena for high definition video and audio with personal computers and in-home theater systems. Due to the off-the-shelf availability of hardware and software that support these interfaces, DVI and HDMI present the opportunity to provide the aircraft industry and the war-fighter with high-quality high-definition video capabilities today.
The signaling format, cable/connector system specifications, and the resulting off-the-shelf cable assemblies for DVI and HDMI were designed to meet the electromagnetic interference (EMI) requirements stated in Part 15 of the Federal Communication Commission (FCC) Rules and Regulations for digital devices, as well as those applicable under the electromagnetic compatibility (EMC) Directive.
The EMI requirements for defense/aerospace equipment are much more severe than those applicable under FCC Part 15 and the EMC Directive. For example, defense/aerospace emissions requirements, such as those called out in MIL-STD-461 E and DO-160E, in addition to being one or two orders of magnitude more stringent, often extend to frequencies below 2 MHz and always require peak detection, compared to a low frequency bound of 30 MHz and the allowance for quasi-peak and average detection found in the non-defense/aerospace sector radiated emissions requirements. Radiated radio-frequency (RF) susceptibility requirements for defense/aerospace equipment are typically at the 200 V/m level, with requirements as high as 8 kV/m in the 1 to 2 GHz band for Army helicopter equipment. Non-defense/aerospace equipment is typically tested at 5 to 10 V/m per standards applicable to the EMC Directive for consumer electronics.
Defense/aerospace equipment is often also subjected to connector pin injected transients with open circuit voltages and currents typically in the ranges of 600 volts and 25 amperes, respectively, and cable or ground injected transients with amplitudes typically in the range of 600 to 1000 Amperes per DO-160E for civil aircraft equipment approval testing. These “indirect effects” transients are representative of the environment produced on the aircraft wires and cables when lightning strikes the aircraft vicinity. Since the equipment on defense/aerospace platforms is often necessary for safe flight and/or mission accomplishment, damage and/or upset from an occasional transient is often an unacceptable consequence.
Consequently, it would be advantageous if an apparatus existed that is suitable for transmitting with a DVI interface in a defense/aerospace environment.